1. Field of the Invention
The present invention generally relates to gas meters, and, more particularly, to a modular gas meter assembly and associated manifold for permitting independent attachment and detachment of a gas meter, pressure regulator, and valve.
2. Description of the Prior Art
With reference to FIG. 1, a typical gas meter installation comprises a service valve or on/off valve 10, a pressure regulator 20, and a gas meter 40. The service valve 10 is connected to a valve body 14 of the regulator 20 through a straight pipe 12 and the valve body 14 is connected to the meter 40 through a straight pipe 22, elbow 24, and meter bar 30. The gas flows through the valve 10, through the pressure regulator 20, and into an inlet 42 of the meter 40. After passing through a measuring assembly within the meter 40, the gas flows out an outlet 44 and into a house or other structure for consumption. The inlet 42 of the meter is typically located at an upper left portion of the meter 40 and the outlet 44 is typically located at an upper right portion of the meter 40.
As discussed above, the meter installation of FIG. 1, in addition to the individual main components of the service valve 10, regulator 20, and meter 40, has a number of additional pipes, fittings, and other members for interconnecting the valve 10, regulator 20, and meter 40 to each other. These components include the pipes 12 and 22, the elbow 24, the meter bar 30, and nuts 32.
These extra components render it rather difficult to assemble or disassemble the installation and to service the installation. For instance, in order to replace a faulty regulator 20, the regulator 20 must be disconnected from the service valve 10 and from the meter bar 30 by removing pipes 12 and 22 from the regulator 20. A new regulator 20 is then attached to the separate pipes 12 and 22 to join the regulator 20 to the service valve 10 and meter 40.
U.S. Pat. No. 5,257,538 to Spendell provides an example of a more recent type of meter installation. With this type of meter installation, a flowmeter, pressure-control device, and a shut-off valve are installed within a single housing. The flowmeter is permanently installed within the housing while the pressure-control device and the shut-off valve are modularly constructed in two parts and can be removed from the housing.
The meter installation of the type in the Spendell patent offers the advantages of being able to easily replace one shut-off valve for another valve or to replace one pressure-control device for another pressure-control device. This installation can therefore be easily adjusted to suit the needs of a particular application by inserting the appropriate modules.
Although the meter installation of the type in the Spendell patent would be easily installed or removed, the meter installation has some practical problems. For instance, if only the meter is faulty, the entire installation would have to be replaced. While the meters often have a lifetime much longer than some other components within a meter installation, it is common practice in the industry to bring the meters in from the field and cycle the meters through service/maintenance shops to ensure that the meters are accurate and to make any necessary calibration adjustments. Since only the meters need to be removed from the meter installation, it is burdensome and undesirable to remove the entire meter installation including the shut-off valve and pressure regulator.